Oral Collagen Improves Skin Hydration and Elasticity, but Benefits for Wrinkles Remain Unproven

An updated systematic review and meta-analysis of randomized controlled trials found that oral collagen peptide supplementation was associated with improvements in several measures of skin physiology, particularly hydration, elasticity, and barrier function.¹ However, the analysis did not find robust evidence that oral collagen reduces wrinkles or increases dermal density after accounting for study heterogeneity and influential outliers.

Study Methodology

The investigators undertook the analysis to address limitations in previous reviews, including differences in collagen sources, molecular weights, doses, formulations, treatment durations, and outcome definitions.² The analysis was conducted via PubMed, the Cochrane Library, and Google Scholar searches through November 30, 2025, and included human randomized controlled or controlled clinical studies that evaluated oral collagen peptides or collagen-based nutricosmetic supplements against a placebo or control group. Studies involving topical collagen, substantial coadministration of other active ingredients, or participants with dermatologic diseases were excluded.

The analysis evaluated objective measures of skin hydration, elasticity, wrinkle depth or number, and dermal collagen content, with skin thickness, transepidermal water loss (TEWL), and adverse events assessed as secondary outcomes. The researchers used several approaches to test the robustness of their findings, including multilevel meta-analysis, leave-one-out sensitivity analyses, dose-response modeling, and publication-bias assessments.

Physiological Benefits and Duration vs. Dosage

The strongest and most consistent findings involved physiological measures. Across the available evidence, oral collagen was associated with a standardized mean difference (SMD) of 0.44 for hydration, 0.62 for elasticity, and −0.39 for TEWL, indicating improvements in skin hydration, elasticity, and barrier function. Sensitivity analyses supported the findings for elasticity and TEWL, with the multilevel model producing an SMD of 0.81 for elasticity and −0.32 for TEWL at 12 weeks.

Treatment duration appeared to be more important than dose. Meta-regression did not identify a significant linear relationship between daily collagen dosage and improvement in outcomes. Hydration benefits appeared as early as 4 weeks, whereas improvements in elasticity and TEWL were primarily observed at 12 weeks. The analysis did not establish evidence that higher doses produced greater benefits.

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Limited Evidence for Structural and Anti-Wrinkle Effects

In contrast, findings for visible wrinkles and structural measures were less convincing. Although the initial analyses suggested potential benefits for wrinkles and skin density, these effects did not remain robust after sensitivity testing. The multilevel analysis found an SMD of −0.02 for wrinkles, while the apparent benefit for skin density was considered likely to represent a type I error. The authors therefore concluded that the evidence did not demonstrate reliable structural benefits in these areas.

The investigators also identified widespread publication bias, with evidence suggesting that smaller negative studies may have been underrepresented. However, adjusting for missing studies still did not produce a meaningful improvement in wrinkles, supporting the conclusion that the lack of effect in this outcome was not simply attributable to publication bias.

Clinical Takeaways and Future Research Needs

Overall, the findings suggest that oral collagen peptides may have their most reproducible effects on skin hydration, elasticity, and barrier function rather than on visible structural changes such as wrinkles or dermal densification. The authors emphasized that substantial variation among collagen formulations and outcome measures, along with predominantly short follow-up periods, limits interpretation of structural outcomes. They called for standardized formulations, harmonized outcome measures, and studies lasting at least 24 weeks to better assess the potential long-term effects of oral collagen supplementation.

References

1. Batool A, Abbas MS, Farooq R, et al. Oral Collagen Peptides and Skin Rejuvenation: A Systematic Review and an Updated Meta-Analysis of Randomized Controlled Trials. J Cosmet Dermatol. 25, no. 7 (2026): e71041. doi:10.1111/jocd.71041

2. Myung SK, Park Y. Effects of Collagen Supplements on Skin Aging: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Am J Med. 2025;138(9):1264-1277. doi:10.1016/j.amjmed.2025.04.034